The Make Noise Soundhack Spectraphon is an advanced dual digital oscillator module for Eurorack synthesizer systems, with a design based on Buchla-style complex oscillators, additive synthesis, and resynthesis.
NEW Firmware Update: SpectraNoise is available now as a free download.
While the typical complex oscillator derives much of its sonic interest from analog waveshaping, Spectraphon takes a different approach entirely: you can think of it as an oscillator whose instantaneous timbre is driven by external audio sources. In fact, it generates its output spectra by analyzing and re-creating the overtone characteristics of other sounds—by way of a clever, intuitive implementation of resynthesis.
Spectraphon is a dual oscillator module with a physical layout somewhat similar to the typical Buchla-style complex oscillator—however, rather than having different "Principal" and "Modulation" oscillators, each of Spectraphon's oscillators is nearly identical. Each offers a variety of outputs, including a sine wave output, Sub/CV output, and Odd and Even harmonic outputs. The Odd and Even harmonic outputs can be shaped and manipulated by a variety of onboard controls: Slide, Focus, and Partials all affect the sound at these outputs. Like a typical complex oscillator, Spectraphon features a central modulation bus, which enables inter-oscillator frequency modulation. Interestingly, FM in Spectraphon affects only the Odd and Even harmonic outputs, and does not impact the oscillator "core" directly; so, you can perform bi-directional FM without inducing chaotic cross modulation. Happily the FM gets insanely deep, perfect for wild, otherworldly sounds.
Spectraphon's oscillators have two modes of operation: Spectral Amplitude Modulation (SAM) and Spectral Array Oscillation (SAO). Each oscillator can be switched to either mode independently of one another. In SAM mode, Spectraphon analyzes audio at the A-In or B-In jacks, and uses it as a means of mapping an overtone structure onto the output of the oscillator in question—instantaneously "resynthesizing" the sound at the Odd and Even harmonic outputs. The nature of the mapping can be altered with the Slide control, shifting the spectral focus up and down the oscillator's own spectrum. The Focus control acts like a sort of spectral "blurring" effect, causing Spectraphon to ring and linger on particularly prominent overtones. The Partials control affects the presence of overtones at the Odd and Even harmonic outputs—completely silent when fully counterclockwise, and increasingly loud/brigt as the knob is turned or external CV is applied. You can think of Partials as being similar to a low pass filter or low pass gate, and it's an excellent place to apply envelopes or other fluctuating CV signals.
At any given moment in SAM mode, you can choose to create an Array of Spectra—during which process Spectraphon captures over 1000 snapshots of the incoming sound over the course of roughly one second. Each of the Spectra are, in essence, an analysis of the sound's overtone characteristics at the moment they were captured. Spectraphon can save sixteen such Arrays for each of the two oscillators. When you switch to SAO mode, you can use these Arrays as the basis of the oscillator's sound. In this mode, the Slide and Focus controls allow you to "scrub" through the array, acting as coarse and fine scrubbing controls, respectively. This enables everything from time-stretched resynthesis of external audio, to reversed sounds, jumbled-up modulated tones, and much more
Spectraphon is full of other tricks. For instance, the Sub/CV outputs can produce clock-able stepped random, smooth random, and triangle LFO outputs; in SAM mode, they can also produce an envelope follower signal, and in SAO mode, they can produce a suboscillator tone. In SAO mode, the A and/or B inputs/knobs can continuously offset the Even harmonic outputs' frequencies. The B oscillator can follow the A oscillator's pitch, or can be hard synced to it. FM and sync work in both SAM or SAO modes, making it possible to frequency modulate external sounds, hard sync resynthesized tones, and much more.
Spectraphon is capable of much more than we can disclose in the context of a simple product listing, but perhaps the key point is this: Spectraphon is Make Noise's most ambitious design to date. It's a complex digital audio processor and sound generator, capable of everything from vocoder-like or resonator-like behavior to the creation of full, multi-voice synthesizer textures. If you want an entirely new approach to additive synthesis and resynthesis, or are just looking for a fresh, unfamiliar sonic flavor for your Eurorack system—Spectraphon is it.
